#lang racket

(define (smallest-divisor n)
  (find-divisor n 2))
(define (?divisor di number) (= (remainder number di) 0))
(define (find-divisor n from)
  (if (?divisor from n)
      from
      (if (> from (sqrt n))
          0
          (find-divisor n (+ from 1)))))
(define (?prime n) (smallest-divisor n))
(define (prime-test n start-time)
  (begin
    (?prime n)
    (- (runtime) start-time)))
;no desire to do